Mid / Side mic processing – How To?

[GaryWParticipant]

I’m wanting to try some Mid / Side recording, but I’m not sure how to set things up on my Qu-SB via my iPad.

Do I need a mic splitter for the Figure-8 microphone, or can I configure that via my iPad?

[timhumParticipant]

I record MS stereo a lot. Not on the QU mixer though. It is a simple matter to do the MS to LR matrixing in the mix down process after the recording session using any of the plugins available but also you can DIY by duplicating the M and S tracks and inverting one S track and calling it the R channel. I monitor on headphones on location and am happy just to make sure the M and S are recorded at a sensible level and not distorting etc.The beauty of the MS technique is that you do all the adjustments in post production, not during the recording.

If I wanted to monitor in LR stereo during the recording with a QU mixerI would use the Aux sends and send the feeds to a headphone amp with a MS matrix or use a cheap 4 line input mixer to turn MS into LR as above.

[[XAP]BobParticipant]

Inputs on the QU mixers aren’t assignable – inputs on the Stage Boxes are.

So if you need a mic sent to two places then you can either:
– Use a stage box (shared preamp)
– Use an analogue split
– If you’re only recording this and need relatively little ‘different’ processing then pull it in on a single channel, route those to Mixes and use the Mix processing. Then record the Mixes rather than the channel…

[GCumbeeParticipant]

Timhum. That doesnt complete the process. You left out the C mic.
Place a figure 8 on edge to the source then place a cardioid mic facing the source with the figure 8 right behind it facing left and right. The figure is split to 2 channnels panned left and right with one out of phase. The blend the cardioid mic up nearly equal to the LR. That’s a M/S process poor mans style.

I also had a box built years ago by Rapco that was a M/S out. Based on a configuration design by Jensen transformers.

[GaryWParticipant]

Awesome help guys, many thanks!

[airickessParticipant]

FYI, just because the mic can do a figure-8 pattern doesn’t mean it puts out a stereo signal (I’m looking at you, AKG C414). Make sure the mic you are using for the figure-8 pattern actually puts out a stereo signal for your recording.

[GaryWParticipant]

Thanks I’ll be sure to watch out for that

[GCumbeeParticipant]

A C414 is not a stereo mic. Only a very few mics put out a stereo signal. Speciality types. You must mult or split the mono mic and reverse phase of one side or use a matrix unit.

[MarkPAmanParticipant]

airickess – I think you misunderstand the M/S technique.

You need a figure-8 and a cardioid mic for M/S recording. You only need record each one, using just two channels, as the “processing” is done later, in the studio. You create a two copies of the figure-8 mic, one with with the polarity reversed. You then pan these hard L+R, then mix with the centre mic to adjust the perceived width.

The AKG C414 is actually a very good mic for M/S recording, and, as it can perform both tasks, is a very useful thing to have a pair of – I wish I did!

[GaryWParticipant]

Thanks guys for all the help!!

[timhumParticipant]

Thanks for the corection GCumbee,
You are right of course. The centre cardioid goes to both left and right and the fig8 as I described it.
I was amiss in omitting that detail.
I recorded a concert last year with a fig 8 centre mic along with the fig8 “S” mic. The advantage was supposed to be that you could rig the mic a little closer to the orchestra and cheekily do another MS decode (with the centre mic phase reversed and the “S” mic phase reverse going to the Left instead of Right)) to add a controlled amount of hall ambience. Easy enough to do in post production and was quite effective but it only works if you have a nice acoustic in the hall of course.

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